UTILIZATION OF CHLORINATED S-TRIAZINES BY A NEW STRAIN OF KLEBSIELLA-PNEUMONIAE

A bacterium utilizing 2-Chloro-4,6-diamino-s-triazine (CAAT) as sole n itrogen source was isolated under a N-2-free atmosphere and identified as Klebsiella pneumoniae. Concomitant to CAAT degradation the protein content increased and chloride was released into the medium. Under ai r and a N-2-atmosphere no reduction of CAAT degradation resulted, thou gh this strain is able to fix molecular nitrogen, but the decompositio n accelerated under anaerobic conditions. The degradation rate increas ed continuously with increasing CAAT concentration. A continuous CAAT degradation without CAAT accumulation was possible up to a influx rate of 4.8 mu mol.1(-1)h(-1) (dilution rate = 0.007h(-1)). K. pneumoniae A2 was also able to utilize deethylsimazine (CEAT) and deethylatrazine (CIAT) as nitrogen source. Both under aerobic and anaerobic condition s CEAT could be degraded faster than CIAT. The degradation sequence of mixed s-triazines was cyanuric acid < CAAT < CEAT < CIAT, which was r eflected by the degradation times of single compounds. Complete degrad ation was assumed for all investigated s-triazine derivatives.